Tutorial quote: this is simple tutorial how to recover you data from a damaged disk.Like dd, dd_rescue does copy data from one file or block device to another.dd_rescue is a tool to help you to save data from crashed partition. It tries to read and if it fails, it will go on with the next sectors where tools like dd will fail. If the copying process is interrupted by the user it is possible to continue at any position later. It can copy backwards.